Extreme pressure lubricant



Patented Feb. 20, 1940 PATENT OFFICE 2,190,715 mraamc mmssunn LUBRICANT Jersey No Drawing. Application Jan 16, 1937 Serial N0. 120,935

13 Claims,

An extreme pressure lubricant differs from the ordinary lubricant in that it lubricates bearings in action under very high pressures without the bearings being seized and thus rendered useless. When seizurev takes place the bearings cease to function smoothly and they are gouged or roughened. When tested with the Almen machine, an ordinary hydrocarbon lubricating oil seizes when a pressure of about 3,000 oi 4,000 pounds per square inch is applied. To meet modern requirements, as, for example, in the automotive industry, it is necessary to provide lubricants which will avoid seizure when the Almen machine is operated under a pressure not less than 15,000 pounds and-that the torque, at-

that pressure,'should not exceed 45 foot pounds.

It is known that when certain materials, in proportions varying from one to five per cent, are added to ordinary lubricating oils, such oils will be converted into high pressure lubricants. Some of them, however, when tested with the Almen machine, will "seize at a considerably lower pressure than 15,000 pounds. One or more of them, however, are capable of passing through the Almen machine at a pressure of 15,000

pounds with a torque below 40 foot pounds, but when run in a transmission for 24 hours the lubricant loses its extreme pressure quality; in other words, it has no permanency as an extreme pressure lubricant under conditions of actual use.

Besides imparting to ordinary lubricating oil the property of withstanding pressures not less than that above specified and enabling the oil to retain such property for a period of running time approximating that expected and required of ordinary lubricating oil in actual commercial use, the added materials, in order to be unobjcctionable and secure high efficiency in connection with their. employment, must possess the following properties:

They must be completely and readily soluble in the hydrocarbon lubricant to which they are added and they must not change the natur appearance of such lubricant. I

They must not be soluble in water or react with water at ordinary atmospheric temperature.

They must not be volatile when the oil heats Iup to a temperature of about 150 C. at 760 mm.

They must not attack or corrode the metal bearings.

At a pressure of 15,000 pounds, the torque must not exceed 45 foot pounds.

Under the conditions of actual operatiom when highv pressures and temperatures are attained, they must not. react ,with the lubricating oil or be themselves decomposed when heated to a temperature of approximately 150 C.

To satisfythe property of permanency, the lubricant must maintain its efliciency when used in a transmission operated continuously for a 5 period of hours at a temperature of approximately 0., which satisfies the conditions of actual operation.

Extreme prwsure lubricants embodying our I invention possess all the properties above enuit merated and are believed, therefore, to satisfy every requirement for an extreme pressur lubricant.

After preparing and testing more than 400 different compounds, we have discovered that when M either normal prbpyl benzene or iso propyl benzene is treated with phosphorus trichloride, in the presence of aluminum chloride as a catalyst,

a product or products are obtained which fulfill all of the requirements demanded of a compound a which, when added to ordinary lubricating oil to the extent, of less than 3 percent converts it into an extreme pressure lubricant having all the properties above specified.

We have, also discovered that when any of 25 th butyl benzenes are treated with phosphorus trichloride, in the presence of aluminum chloride as a catalyst, products are obtained which, when added to ordinary lubricating oils to the extent of less than 3 percent, converts such lubricating oil into an extreme pressure lubricant having all theproperties above specified.

In preparing these compounds we proceed as 4 follows, using proply benzene as an example.

The reaction vessel is made of glass or of porcelain-lined metal or of aluminum or of any alloy which will not react with the hydrochloric acid evolved to form reaction products which might act '-as deleterious catalysts. (Although aluminum reacts with hydrochloric acid, the resulting aluminum chloride is a desirable catalyst.) 3 The reaction vessel is provided with a mechanical stirrer, an inlet, an outlet, and a condenser. The propyl benzene'is run into the 'reaction vessel and, for each kilogram of propyl benzene employed about 20 grams of anhydrous aluminum chloride is added. Then phosphorus. trichloi'ide is slowly introduced, the amount being about one mole for each mole of propyl benzene used. The reaction starts at once, heat is generated, and hydrochloric acid is evolved through the top of the condenser and absorbed in water. After the preliminary reaction has subsided, the'vessel is heated until no more I hydrochloric acid is evolved (24 to48 hours).

remains in the bottom), is fractionated, imder ill chlor phosphine.

diminished pressure, and a final cut is collected between about 100 C. and about 155 C. at 20 mm. The resulting product, consisting largely of propyl benzene dichlor phosphine, may be further purified, if desired, by fractional distillation. The pure. (iso) compound boils at 268- 270" C. at 760 mm. of mercury or at about 140- 150 C. at 20mm. of mercury. The crude product may be efliciently employed as produced, or it may be further purified by redistillation, as above indicated, and then washed with water in order to remove the last traces of hydrochloric acid; The product is readily soluble in hydrocarbon oils' and is insoluble in water and is not decomposed by water at ordinary atmospheric temperature. It is soluble in ethyl alcohol, benzene, carbon, tetrachloride, and acetone. It is stable at its' boiling point The tar-like catalytic complex remaining in the bottom .of thereaction vessel may be treated with cold water, a small amount of water being added at a time. The reaction between the water.

and the catalytic complex is quite vigorous. After the decomposition has been effected, a dark colored tarry mass separates on top of the water. This is washed several times with water, dried,and finally distilled, under a partial vacuum. A cut taken between about 100 C. and about 155 C. at 20 mm. proved to be composed principally of the anhydrous aluminum chloride; and it will be understood that in our process the-two catalysts are equivalents.

Butyl benzene dichlor phosphine may be prepared by substituting butyl benzene for propyl benzene and proceeding in the manner above. described for the preparation of propyl benzene di- The crude butyl product boils between about .110 C. and about 170' C. at 20 mm., corresponding to a boiling point of from about 220 C. to about 290 C. at 760 mm. It is readily soluble in hydrocarbon oils and is insoluble in and not decomposed by water. It is soluble in ethyl alcohol, benzene carbon tetrachloride, and acetone. boiling point.

In the preparation of either propyl benzene dichlor phosphine or butyl benzene dichlor phosphine, there are formed minor proportions of other'compounds of varying boiling points that are derivatives of phosphine. Thus, in the preparation of propyl benzene dichlor phosphine, there are formed propyl benzene monochlor phosphine and particularly dipropyl benzene monochlor phosphine, and possibly tripropyl benzefie phosphine and phosphine. ,So in the preparation of isomeric butyl benzenes there are formed corresponding compounds. Due to the iorrnation of It is relatively stable atits decomposition products by the action of anhydrous aluminum chloride on the alkylated benzenes, and due to the formation of varying minor amounts or the compounds above named, the boiling points of the products vary over a wide range. In claiming propyl benzene or butyl benzene, we mean to include all of the possible isomeric compounds included under each term. Propyl benzene dichlor phosphine and butyl benzene dichlor phosphine comprise all substances of a class which is definable as alkyl benzene dichlor phosphine in which the alkyl group contains from three to four carbon atoms; and in those claims wherein the lubricant is defined as containing alkyl benzene dichlor phosphine in a which the alkyl group contains from three to four carbon atoms, such term is intended to include only propyl benzene dichlor phosphine and butyl benzene dichlor phosphine. So also mono propyl benzene and mono butyl benzene comprise all substances of a class which is definable as monoalkylated benzene in which the alkyl group contains from three to four carbon atoms; and in those claims wherein the lubricant is defined as containing a minor percentage of the reaction products ofmono alkylated benzene, in which the alkyl group contains from three to four carbon atoms, when reacted asdescribed, we mean to include only the reaction products of mono propyl benzene and mono butyl benzene.

The percentage of any of the described compounds whichmust be added to ordinary lubricating oil to convert it into a high pressure lubricant cannot be arbitrarily stated, since a percentage substantially less than that required to secure high efiiciency will impart to the oil the properties desired to a material extent. Generally speaking, the percentage added should not be lessthan 1 percent. Between 2 and 3% will impart to the oil the desired qualities in maximum degree, and while this larger proportion may be materially exceeded, the excess will have no beneficial effect.

In order to determine the durability of these products, when dissolved in lubricating oils and employed under actual conditions of.use, tests were made in a transmission removed from a 1936 Chevrolet car. on a frame and connected to a shaft of a motor running at a'speed of 1725 R. P. M. Twoand onehali percent, by weight, of the product (e. g. propyl benzene dichlor phosphine) was dissolved in ordinary lubricating oil having a viscosity of 1'60. The oil was placed in the transmission and heated, by means of'an electric thermostatically controlled resistance, to a'temperature of 120 C. This temperature was maintained throughout the entire run. The motor was started and the transmission run continuously for a period of 100 hours. Samples were .removed tor testing after every 24 hours during the run. During this 100 hour test the shaft revolved 10,350,000 times. Upon completion of the 100 hour run, samples of the, oil were removed andpassedthrough the Almen machine at a pressure of 15,000 pounds per square inch, and the torque was below 45 foot pounds. The same test, with the same result, was made with the same lubricating oil containing two and one-half percent of butyl benzene dichlor phosphine. Thus, conclusive evidence was aflorded oi the lasting properties of the compounds mentioned, under conditions of actual employment.

The transmission was mounted- A1 ,careful examination of the gears of thistransmission, before and-after these runs, indicated that no corrosion took place when the two I pressures, is lower than when the lard oil or the above mentioned acids are absent. The addition of as little as one percent of either of these ingredients has an appreciable effect of the character specified, but we prefer to add about five percent, which is effective to notably improve the product in the respect mentioned. The addition of a larger proportion, up to or even, possibly, above ten percent, is permissible, but effects no marked improvement over that secured by the addition'of the preferred percentage mentioned and is objectionable on account oi the added expense. I

What we claim and desire to protect by Letters Patent is:

1. An extreme pressure lubricant comprising lubricating oil containing a minor. percentage of alkyl benzene dichlor phosphine in which the alkyl group contains from three to four carbon atoms.

2. An extreme pressure lubricant comprising lubricating oil containing a minor percentage of propyl benzene dichlor phosphine. v

3. An extreme pressure lubricant comprising lubricating oil containing a minor percentage of butyl benzene dichlor phosphine.

4. An extreme pressure lubricant comprising lubricating oil containing a minor-percentage of the reaction products of mono alkylated benzene,

of the reaction products of mono butyl benzene reacted with phosphorus trichloride in the presence of aluminum chloride as a catalyst.

7. An extreme pressure lubricant in accordance with claim 4 which will not corrode metallic bearings, which is insoluble in water, which is relatively stable at the temperatures and pressures encountered during the operation of high pressure bearings and whose extreme pressure] properties will, therefore, not decrease with extended use.

8. An extreme pressure lubricant in accordance with claim 5 which is insoluble in water.

which is relatively stable at the temperatures and pressures encountered during the operation of high pressure bearings and whose extreme pressure properties will, therefore, not decrease with extended use.

9. An extreme pressure lubricant comprising lubricating 011 containing a minor percentage of the reaction products of mono alkylated benzene, in which the alkyl group contains from three to four carbon atoms, reacted with phosphorus trichloride in the presence oi. aluminum chloride as a catalyst, and containing also a small percentage of lard oil.

10. An extreme pressure lubricating oil comprising lubricating oil containing a minor percentage of the reaction products of mono propyl benzene reacted with phosphorus triohloride in the presence of aluminum chloride as a catalyst,

and containing also a small percentage of lard oil..

11. An extreme pressure lubricating oil comprising lubricating oil containing a minor percentage of the reaction products of mono butyl benzene reacted with phosphorus trichlorlde in the presence of aluminum chloride as a catalyst,

lard oil.

13. An extreme pressure lubricant in accordance with claim 6 which is insoluble in water. which is relatively stable at the temperatures and pressures encountered during the operation of high pressure bearings and whose extreme pres sure properties will, therefore, not decrease with extended use.

m EDWARD JOLLY. I JOHN HAROLD PERRINE. 

